RESUMEN
A total of 336 one-day-old Hubbard broiler chickens were randomly distributed among 8 groups, each containing six replicates (7 chickens/replicate). From 1 to 40 days of age, the groups fed the same starter, grower and finisher diets. The control group was unsupplemented; zinc bacitracin (ZnB) group received the antibiotic at 0.5 g/kg; fungal phytase (FP) groups received 250, 500 and 1000 U/kg diet of Aspergillus niger phytase (FP_250, FP_500 and FP_1000 groups), respectively; bacterial phyatse (BP) groups received 250, 500 and 1000 U/kg diet of Escherichia coli phytase (BP_250EP, BP_500EP and BP_1000EP groups) respectively. Considering the whole experimental period, body weight gain was unaffected by ZnB and different concentrations of bacterial and fungal phytase; however, the feed conversion ratio of the group fed a diet supplemented with 500 U of BP was better (p < 0.01) than those fed with a diet supplemented with 500 U of FP. BP_250 group had a higher (p < 0.05) apparent digestibility of ether extract compared to FP_250 group. In conclusion, bacterial phytase at 500 U may enhance performance of broiler chickens fed during days 1-40 of age and yield similar growth performance and economic efficiency to those of eB-supplemented groups.
Asunto(s)
6-Fitasa/farmacología , Antibacterianos/farmacología , Bacitracina/farmacología , Digestión/efectos de los fármacos , Carne/normas , 6-Fitasa/administración & dosificación , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Antibacterianos/administración & dosificación , Aspergillus niger/enzimología , Bacitracina/administración & dosificación , Pollos/crecimiento & desarrollo , Dieta/veterinaria , Digestión/fisiología , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Escherichia coli/enzimología , Femenino , Masculino , Aumento de Peso/efectos de los fármacosRESUMEN
In order to investigate the effect of different levels of oral glucose supplementation and/or reproductive method on productive and reproductive performance of New Zealand White (NZW) doe rabbits in the tropic, 36 bucks and 120 doe NZW rabbits were equally divided among four treatment groups (n = 9 bucks + 30 does). The treatments consisted of supplementing drinking water with 0 (control), 2.5, 5 and 10 g glucose/l, respectively. To study the effect of reproduction method (natural v. artificial), each group was divided into two sub-groups (naturally mated and artificially inseminated) with the same bucks of the same treatment group. Glucose supplementation at 5 or 10 g/l of water increased (P < 0.01) litter weight at birth and at weaning, and litter weight gain during the 4 weeks. However, glucose supplementation at 2.5 or 5.0 g/l water decreased (P < 0.01) feed consumption from 7 to 14 days after delivery. Glucose supplementation at 2.5 g/l water did not affect productive and reproductive performance of rabbits. Artificially inseminated does had higher daily litter weight gain between 21 and 28 days post partum. Artificially inseminated group had better milk conversion during the 1st and 4th week as compared to naturally mated groups. Compared with the control group, the economic efficiency and performance index of NZW rabbits was significantly improved by 5 g glucose supplementation under tropic condition.